线程池

线程池可以说是把之前所有的内容全部串联起来的一个项目

我们这里实现一个简单的版本，可以对其进行扩展

线程池也是一种生产者消费者模型

生产者布置任务而消费者处理任务

主要运用的场景是需要大量现场完成任务，任务完成时间较短，例如WEB服务器中的网页请求

线程池的使用非常简单

就是创建固定数量的线程，然后往任务列表里推送任务即可

线程池会自动分派线程去完成

我们将之前的所有内容可以串联起来做一个小型项目，非常建议阅读并自行实现，写代码才是学习编程的最好方式

1. 互斥锁和信号量封装
2. 线程库封装
3. 日志系统

日志系统完善

这里主要完善了日志系统写的方式，可以向屏幕输出、单个文件输出、按照等级划分的文件输出

借用了隔壁日志系统的代码，那边也还没写完

#pragma once
#include "level.hpp"
#include "format.hpp"
#include "util.hpp"
#include <fstream>const std::string logdir = "./log/";enum WriteStyle
{Screen = 114, // 屏幕打印OneFile,      // 全部打印到一个文件ClassFile     // 按等级分类打印
};void WriteToOneFile(const std::string &str, const std::string &logname = "logALL")
{Xulog::Util::File::createDirectory(logdir);std::string fullLogName = logdir + logname;std::ofstream out(fullLogName, std::ios_base::app);if (!out.is_open()){std::cout << fullLogName << ":文件打开失败" << std::endl;}out.write(str.c_str(), str.size());out.close();
}void WriteToClassFile(const std::string &str, Xulog::LogLevel::value val)
{std::string logname = "log";logname += Xulog::LogLevel::toString(val);WriteToOneFile(str, logname);
}void WriteLog(Xulog::LogMsg msg, Xulog::Formatter fmt, WriteStyle style = Screen)
{std::string str = fmt.Format(msg);switch (style){case Screen:std::cout << str;break;case OneFile:WriteToOneFile(str);break;case ClassFile:WriteToClassFile(str, msg._level);break;}
}

线程池的实现

线程数据

定义一个ThreadData，用于获取当前线程的信息，可以添加别的信息，例如创建时间，运行时间等

class ThreadData
{
public:ThreadData(const std::string &name): threadname(name){}~ThreadData() {}std::string threadname;
};

线程池的实现

#pragma once
#include "Thread.hpp"
#include "LockGuard.hpp"
#include "write.hpp"
#include <iostream>
#include <queue>
#include <vector>
#include <functional>
#include <unistd.h>static const int THREAD_NUM = 5;
Xulog::Formatter fmt;class ThreadData
{
public:ThreadData(const std::string &name): threadname(name){}~ThreadData() {}std::string threadname;
};template <class T>
class ThreadPool
{
public:ThreadPool(int thread_num = THREAD_NUM): _thread_num(thread_num){pthread_mutex_init(&_mutex, nullptr);pthread_cond_init(&_cond, nullptr);// 构建线程for (int i = 0; i < _thread_num; i++){std::string threadname = "thread-";threadname += std::to_string(i + 1);ThreadData td(threadname);_threads.emplace_back(threadname, std::bind(&ThreadPool::ThreadRun, this, std::placeholders::_1), td);Xulog::LogMsg msg(Xulog::LogLevel::value::DEBUG, 0, "default", td.threadname.c_str(), "线程已经启动");WriteLog(msg, fmt);}}void ThreadRun(ThreadData &td){while (true){// 取到任务T task;{LockGuard lockguard(&_mutex);while (_task_que.empty()){ThreadWait(td);}task = _task_que.front();_task_que.pop();}// 处理任务task();Xulog::LogMsg msg(Xulog::LogLevel::value::DEBUG, 0, "default", td.threadname.c_str(), "任务已经完成,结果是:" + task.PrintResult());WriteLog(msg, fmt);sleep(1);}}void ThreadWait(ThreadData &td){Xulog::LogMsg msg(Xulog::LogLevel::value::INFO, 0, "default", "root", td.threadname + "休眠了");WriteLog(msg, fmt);pthread_cond_wait(&_cond, &_mutex);}void ThreadWeakUp(){pthread_cond_signal(&_cond);}bool Start(){// 启动线程for (auto &thread : _threads){thread.Start();}return true;}void Push(const T &in){Xulog::LogMsg msg(Xulog::LogLevel::value::DEBUG, 0, "default", "root", "生成了一个任务,任务是:" + in.PrintTask());WriteLog(msg, fmt);LockGuard lockguard(&_mutex);_task_que.push(in);ThreadWeakUp();}void Wait() // 调试方法{for (auto &thread : _threads){thread.Join();}}~ThreadPool(){pthread_mutex_destroy(&_mutex);pthread_cond_destroy(&_cond);}private:std::queue<T> _task_que;std::vector<Thread<ThreadData>> _threads;int _thread_num;pthread_mutex_t _mutex;pthread_cond_t _cond;
};

完整代码

线程池+日志系统(github.com)